California Governor Jerry Brown has emerged as the default climate leader for the US. At the COP23 climate conference in Bonn, Brown tells DW's Environment Editor Sonya Diehn what it takes to beat Trump on climate.

Jerry Brown: First of all, it's to say to the rest of the world that America is in — we're in the Paris Accord. We have to keep the temperature below a 2-degree centigrade increase, and we're going to do that not with the federal government, because the federal government is on holiday with respect to climate change.

But California, New York is in — also the states of Washington, Oregon, Virginia, New Jersey. And then in addition in the states, we have cities hundreds of cities. We have corporations and universities. We represent almost half of America.

So there is a large part of America — well over a majority — that is committed to serious climate action, because we know global warming is an existential threat. If we don't get at it right away with decisive steps, we'll all suffer, and all the problems we have now from immigration to extreme weather events, inequality, will all get worse. America's Pledge is filling the gap left by Donald Trump's statement that he was to pull out of Paris.

Most Americans want climate action, Brown says

Do you believe that local and state government policy and action can make up the difference?

No, they can't make up the difference. But instead of doing nothing, we're doing something — pending a new president or pending a conversion experience on the part of Donald Trump, because his statement that he believes climate change is a hoax created by the Chinese government is so preposterous, it's such a fairytale, that it's hard to believe that he believes it. Maybe he'll change his mind when other pressures come to bear.

California's already working on emission reductions, and is making progress in sectors like energy and mobility. How does it plan to decarbonize?

And there we want to get zero-emission vehicles. We want the German automakers to realize we want zero-emission vehicles — we don't want those old diesel vehicles, even if they fix this problem. We have to go to the "new" — that's what China wants, that's what California wants. And together, we are the biggest market.

At the "America's Pledge" event, protesters said that oil produced in California is among the world's dirtiest, and they accuse California of having oil-friendly policies. Is a phase-out of oil production in California planned, especially considering the limited carbon budget that we have left?

Yes, some of the oil — but not all the oil — is pretty dirty. And yes, we will be able to phase down production. But it would be somewhat hypocritical to say that in California, where we have stringent environmental controls on oil drilling, that we will shut that down and we'll go to other countries, where there are far poorer people, with far worse pollution and very lax environmental rules.

Brown has come under fire at COP23 for California's oil production policies

Well, if we stopped the 32 million cars [and] said you can't use oil, the whole economy would collapse. You'd have a revolution. There'd be shooting in the streets — and you couldn't do that, and no one would do that. So what you're saying is, stop the energy that goes into all these cars, but don't stop the cars. And it's not coherent. Now, yes, we will phase-down our oil consumption, but we have a plan: a cap, a limit on GHGs.

This is a very imbedded industry, and we need a very sophisticated response to minimize it. So I understand what people are saying, but it's part of a bigger picture. And gestures are not helpful — we need strategies and action.

California will follow in the footsteps of other cities around the world introducing e-buses on a mass scale

California has special legal status in the United States to be able to establish its own regulations in areas like air pollution — but this could be challenged by the federal government. Do you think that will happen, and if so, what might be the outcome?

Well, we've been challenged before: Under the Bush administration, the California emission rules were challenged, and we only overcame that challenge with the election of Obama. But now, under the Obama administration, our California rules were placed into regulation. That is an evidence-based process — and Trump just can't change a rule. He has to go through an evidence-based process. And the independent courts will make sure that process is honest and has integrity.

So I think that he will be long gone before our policies are in any way changed.

How do you see the future of the federal US government with relation to the Paris Agreement?

I think the federal government is treading water. They've kind of become like Saturday Night Live, or a comedy program. They're bringing in a coal company to teach the Europeans how to clean up the environment. So it's almost double-speak [like in George Orwell's 1984]. So no one's going to take it seriously. But the bubble of the extreme radicals that support Trump — they love it. It's red meat for them. They chew on it, and feel good, but they represent no more than 35 to 40 percent.

Trump's approach to climate has become a joke abroad, Brown says

How about the argument that a switch to renewable energy is going to cost a lot of jobs?

That is one of the silly stories that we call a "Trumpism." The truth of the matter is that California, with its strong renewable energy, its very far-reaching greenhouse gas reduction set of policies — our economy grows faster than the national average. So, I think that is very good proof that green energy, wind, solar, new electricity grid, battery storage, electric cars, hydrogen cars — all of these create new jobs, the jobs of the future.

What can people do? What is your message to the people?

The people can vote for candidates who take climate change seriously. Number two, they can change their own behavior: in the cars they drive, or how often they walk, the meals, the way they cook, the technologies that they buy, even something as simple as lightbulbs. We can all do our part — but individually, it won't be enough. We need collective leadership on the part of governments everywhere to really decarbonize the world. And that's what I'm committed to seeing done.

Edmund Gerald Brown Jr. has been the 39th Governor of California since 2011.

How to stop climate change? Start now!

Number 10: Upgrade lightbulbs

You just bought a fancy lamp? Make it cooler with efficient lightbulbs. This is one of the small actions that make a difference in the long-term - and let's be honest, it's not a big effort. Some LED bulbs consume up to 90 percent less than traditional ones.

How to stop climate change? Start now!

Number 9: Hang laundry to dry

In cold or rainy countries, the task might be challenging - but these challenges are nothing compared to the worst consequences of climate change.

How to stop climate change? Start now!

Number 8: Recycling

Recycling has become normal behavior for thousands of people around the world. It definitely contributes to making a better world - but unfortunately, it is not enough.

How to stop climate change? Start now!

Number 7: Wash clothes on cold

Worried about your clothes shrinking in hot water? Here another reason to keep washing with cold water: Since it avoids turning on the water heater, cold-water washing also produces less greenhouse gas emissions.

How to stop climate change? Start now!

Number 6: Drive a hybrid

Until you are ready to get rid of your car completely, you could move to a hybrid electric car. But beware: The electricity that powers it is probably still coming from dirty fossil fuels.

How to stop climate change? Start now!

Number 5: Switch to a vegetarian diet

Beef production is the largest driver of tropical deforestation worldwide, with soy production closely following - mainly to feed animals. The carbon footprint of a meat-based diet is almost double that of a vegetarian one. Even reducing the amount of meat you eat makes a difference.

How to stop climate change? Start now!

Number 4: Buy green energy

Renewable energies are the new trend - but we are still largely dependent on fossil fuels such as coal. In countries like Germany, you can choose your energy provider - among some that draw from renewable sources.

How to stop climate change? Start now!

Number 3: Cancel one trans-Atlantic flight

Air travel is a major challenge when it comes to tackling climate change. Policy-makers are exploring ways to reduce the climate impact of flights - but in the meantime, you can start thinking twice before taking a plane. Particularly to cross the pond.

How to stop climate change? Start now!

Number 2: Don't use a car

Getting rid of your car is the second-most effective action you can take to tackle climate change. And riding your bike also helps keep you fit!

How to stop climate change? Start now!

Number 1: Have one fewer child

Giving birth to a new person consuming and polluting at the current rate of people in industrialized countries is the worst thing you can do for the planet, according to the study. But if you start now with the other nine actions, your kids might be able to live in a better world.